El Valle is a town built inside an ancient volcano.

About 35 million years ago, all of Central America was under water, and only began to emerge through numerous volcanic explosions which began forming volcanic islands, and through continued explosions, the land-bridge was formed between North and South America. Anton Valley is the location of perhaps the largest and oldest of those volcanoes.Today it is one of the largest volcanic craters in the world, with a mouth that is 6-km-wide. It is the largest inhabited volcano in the world.

Five to ten million years ago, the volcano imploded*, creating the 18.5-square km basin that is now home to 9,000 human beings from 25 countries, as well as 100 different kinds of amphibians (golden frogs and transparent frogs included), 75 classes of reptiles and an amazing 450 species of birds.

* it is a recently-understood phenomenon that extremely old volcanoes eventually implode. 

 At one point the basin was filled with water, but the lake drained into the Pacific Ocean through a crack in the volcanic rim.

The first human inhabitants moved from Altos de La Estancia, behind the Sleeping Indian Girl Mountain (La India Dormida). The first human visitors did not make their residence on the volcanic floor because the ground was wet. The Valley was not inhabited until settlers developed a system to drain the water creating livable space.

Anton Valley is known as a "corregimiento", one of ten that belongs to the District of Anton. By the way, the name Anton refers to Anton Martin, a Spanish pilot that nearly died exploring the Anton River, which is born in The Valley and is the same river that drained and continues to drain the Valley into the Pacific Ocean.

 This year, 2010-2011, The Valley  is celebrating its 100th anniversary as a corregimiento.